1. Field of the Invention
The present invention relates to a method of and an apparatus for recording a two-dimensional image on a photosensitive medium by exposure to light beams which are emitted from a plurality of light sources arrayed in an auxiliary scanning direction and applied to scan the photosensitive medium in a main scanning direction and the auxiliary scanning direction.
2. Description of the Related Art
There have been used exposure recording apparatus in which a drum with a photosensitive medium mounted on its outer circumferential surface is rotated about its own axis in a main scanning direction and the photosensitive medium is scanned with a laser beam that has been modulated by an image to be recorded, in an auxiliary scanning direction perpendicular to the main scanning direction, for thereby recording a two-dimensional image on the photosensitive medium.
One type of such exposure recording apparatus has a plurality of light sources arrayed in the auxiliary scanning direction which can simultaneously be energized to record a large-size image at a high speed (see Japanese laid-open patent publication No. 7-23195). If the positions of images produced by adjacent ones of the light sources are inaccurate relatively to each other, then junctions between recording ranges of the light sources suffer from striped image irregularities.
According to the above conventional exposure recording apparatus, if the positions of images produced by the light sources are misaligned in the main scanning direction, then such a positional misalignment is corrected by delaying or advancing the recording times of the light sources in the main scanning direction by a certain relative period. If the positions of images produced by the light sources are misaligned in the auxiliary scanning direction, then times to start recording images in the auxiliary scanning direction by the respective light sources are adjusted by the number of pixels that is obtained by rounding off the image position misalignment, for thereby correcting a misalignment that is equal to or greater than one half of a pixel.
With the conventional exposure recording apparatus, however, since the times to start recording images in the auxiliary scanning direction by the respective light sources are individually adjusted to record the images with the same number of scanning lines, if the times to start recording images in the auxiliary scanning direction by the respective light sources that are located in recording start positions in the auxiliary scanning direction are adjusted, then the overall position of the recorded two-dimensional image is displaced in the auxiliary scanning direction.
It is a general object of the present invention to provide a method of and an apparatus for recording a high-quality two-dimensional image at a high speed in a desired recording position on a photosensitive medium by exposure to light beams with an inexpensive arrangement without the need for a highly accurate adjusting process and a highly accurate adjusting mechanism.
The above and other objects, features, and advantages of the present invention will become more apparent from the following description when taken in conjunction with the accompanying drawings in which preferred embodiments of the present invention are shown by way of illustrative example.